M2Ti2O5S2 Anode Material for High Voltage Lithium Batteries

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Solution Overview

Problem

Lithium batteries face challenges with low battery voltage due to high electric potential of conventional anode active materials like LTO, and there is a need for materials with higher thermal stability and lower electric potential for improved safety and performance.

Innovation Solution

The use of M2Ti2O5S2 crystalline phase as an anode active material in lithium batteries, where M is Y or Nd, offering lower electric potential and enhanced thermal stability, allowing for increased battery voltage and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LTO is used as an anode active material to improve thermal stability, then safety is improved, but battery voltage is lowered

Engineering Contradiction:
ImprovesafetyVSAvoidbattery voltage
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The invention changes the electric potential parameter of the anode active material by replacing conventional LTO (1.5V) with M2Ti2O5S2 (1.0-1.3V), thereby resolving the contradiction between thermal stability and battery voltage. The new material maintains oxide-based thermal stability while achieving lower electric potential for higher voltage output.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite material M2Ti2O5S2 that combines metal element M with the Ti2O5S2 framework, creating a new class of materials that simultaneously provide thermal stability (oxide characteristic) and low electric potential (intercalation compound property), thus resolving the voltage-safety tradeoff.

Inventive Principle:
Principle #40Composite materials

2Temperature

If Li insertion and extraction electric potential of anode active material is increased to improve safety, then thermal stability is improved, but battery voltage is lowered

Engineering Contradiction:
Improvethermal stabilityVSAvoidbattery voltage
Core Design Contradiction:
TemperatureVSPower

Solution Approach 1:

The invention optimizes the Li insertion and extraction electric potential parameter to 1.0-1.3V, which is higher than carbon materials (ensuring thermal stability) but lower than conventional LTO (maintaining high battery voltage). This parameter optimization resolves the contradiction between thermal stability and voltage.

Inventive Principle:
Principle #35Parameter changes

3Power

If conventional carbon materials are used as anode active material, then battery voltage is maintained, but thermal stability is insufficient

Engineering Contradiction:
Improvebattery voltageVSAvoidthermal stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The invention replaces conventional carbon materials with M2Ti2O5S2 composite materials that exhibit oxide-like thermal stability while maintaining intercalation compound properties for acceptable voltage, thus resolving the voltage-thermal stability tradeoff.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the material composition parameter from carbon-based to M-Ti-O-S-based, fundamentally altering the thermal stability parameter while controlling the electric potential parameter to maintain high battery voltage.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The M2Ti2O5S2 active material provides a lithium battery with higher voltage and improved thermal stability compared to conventional carbon materials, enhancing safety and performance without requiring changes to existing device designs.

Implementation Method 1

Li insertion and extraction electric potential of LTO (oxidation and reduction electric potential) relative to Li metal is about 1.5 V... as the active material has an M2Ti2O5S2 crystalline phase, it can be provided as an active material for a battery having a low electric potential

Methodology Applied
Scientific EffectIntercalation: Absorption (physical)

Data Source

PatentEP2557620B1Active material for battery, and battery
Publication Date: 2017.04.26 TOYOTA JIDOSHA KK
  • EP2557620B1 patent drawingFigure 1~2
  • EP2557620B1 patent drawingFigure 3~4
  • EP2557620B1 patent drawingFigure 5~6

AI summary

The present invention is to provide an active material for a battery, which has high thermal stability and low electric potential. According to the invention, an active material for a battery comprising a M element in Group III, a Ti element, an O element, and a S element and having an M2Ti2O5S2 crystalline phase is provided to solve the problem.